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From Joel Koshy <jjkosh...@gmail.com>
Subject Re: [DISCUSS] KIP-109: Old Consumer Deprecation
Date Tue, 10 Jan 2017 21:57:43 GMT
On Tue, Jan 10, 2017 at 12:53 PM, Renu Tewari <tewarir@gmail.com> wrote:

> Hi Ismael,
> What are the expected timelines we are talking about between the major
> releases? At LI we are expecting to have atleast 1 year between the old
> consumer deprecation and removal so we have enough time to upgrade all
> applications. The rollout to new consumer has hit many hurdles so hasn't
> proceeded at the expected pace. What impact would an official deprecation
> have on applications?  Any warnings would be disruptive and would prefer
> that happens when there is a migration plan in place so we have a bound on
> how long it will take. There are too many unknowns at this time.
>
> Thoughts on timelines?
>
> regards
> Renu
>
> On Mon, Jan 9, 2017 at 6:34 PM, Ismael Juma <ismael@juma.me.uk> wrote:
>
> > Hi Joel,
> >
> > Great to hear that LinkedIn is likely to implement KAFKA-4513. :)
> >
> > Yes, the KIP as it stands is a compromise given the situation. We could
> > push the deprecation to the subsequent release: likely to be 0.11.0.0
> since
> > there are a number of KIPs that require message format changes. This
> would
> > mean that the old consumers would not be removed before 0.12.0.0 (the
> major
> > release after 0.11.0.0). Would that work better for you all?
>

It helps, but the main concern is deprecating before implementing the
migration path. So this means merging in the deprecation PR right after
cutting 0.10.2 is also going to be problematic since we release off trunk.
So we can prioritize working on KAFKA-4513.

@Ewen: good question on message format changes - I agree with Ismael that
for features such as a new compression scheme we can do without a format
change. I don't think we have any formal guidance on the scenarios that you
highlighted at this point so it may help to have a discussion on a separate
thread and codify that in our docs under a new "Kafka message and protocol
versioning" section.

Thanks,

Joel


> >
> > On Tue, Jan 10, 2017 at 12:52 AM, Joel Koshy <jjkoshy.w@gmail.com>
> wrote:
> >
> > > >
> > > >
> > > > The ideal scenario would be for us to provide a tool for no downtime
> > > > migration as discussed in the original thread (I filed
> > > > https://issues.apache.org/jira/browse/KAFKA-4513 in response to that
> > > > discussion). There are a few issues, however:
> > > >
> > > >    - There doesn't seem to be much demand for it (outside of
> LinkedIn,
> > at
> > > >    least)
> > > >    - No-one is working on it or has indicated that they are planning
> to
> > > >    work on it
> > > >    - It's a non-trivial change and it requires a good amount of
> testing
> > > to
> > > >    ensure it works as expected
> > > >
> > >
> > > For LinkedIn: while there are a few consuming applications for which
> the
> > > current shut-down and restart approach to migration will suffice, I
> doubt
> > > we will be able to do this for majority of services that are outside
> our
> > > direct control. Given that a seamless migration is a pre-req for us to
> > > switch to the new consumer widely (there are a few use-cases already on
> > it)
> > > it is something that we (LinkedIn) will likely implement although we
> > > haven't done further brainstorming/improvements beyond what was
> proposed
> > in
> > > the other deprecation thread.
> > >
> > >
> > > > In the meantime, we have this suboptimal situation where the old
> > > consumers
> > > > are close to unmaintained even though we don't say it outright: they
> > > don't
> > >
> > > get new features (basic things like security are missing) and bug fixes
> > are
> > > > rare. In practice, the old clients have been deprecated a while back,
> > we
> > > >
> > >
> > > Agreed that it is suboptimal, but the reality is that LI and I think a
> > few
> > > other companies are still to a large extent on the old consumer and
> will
> > be
> > > for at least a good part of this year. This does mean that we have the
> > > overhead of maintaining some internal workarounds for the old consumer.
> > >
> > >
> > > > just haven't made it official. This proposal is about rectifying that
> > so
> > > > that we communicate our intentions to our users more clearly. As
> Vahid
> > > > said, this KIP is not about changing how we maintain the existing
> code.
> > > >
> > > > The KIP that proposes the removal of all the old clients will be more
> > > > interesting, but it doesn't exist yet. :)
> > > >
> > >
> > > Deprecating *after* providing a sound migration path still seems to be
> > the
> > > right thing to do but if there isn't any demand for it then maybe
> that's
> > a
> > > reasonable compromise. I'm still surprised that more users aren't as
> > > impacted by this and as mentioned earlier, it could be an issue of
> > > awareness but I'm not sure that deprecating before a migration path is
> in
> > > place would be considered best-practice in raising awareness.
> > >
> > > Thanks,
> > >
> > > Joel
> > >
> > >
> > >
> > > >
> > > > Ismael
> > > >
> > > > On Fri, Jan 6, 2017 at 3:27 AM, Vahid S Hashemian <
> > > > vahidhashemian@us.ibm.com
> > > > > wrote:
> > > >
> > > > > One thing that probably needs some clarification is what is implied
> > by
> > > > > "deprecated" in the Kafka project.
> > > > > I googled it a bit and it doesn't seem that deprecation
> > conventionally
> > > > > implies termination of support (or anything that could negatively
> > > impact
> > > > > existing users). That's my interpretation too.
> > > > > It would be good to know if Kafka follows a different
> interpretation
> > of
> > > > > the term.
> > > > >
> > > > > If my understanding of the term is correct, since we are not yet
> > > > targeting
> > > > > a certain major release in which the old consumer will be removed,
> I
> > > > don't
> > > > > see any harm in marking it as deprecated.
> > > > > There will be enough time to plan and implement the migration, if
> the
> > > > > community decides that's the way to go, before phasing it out.
> > > > >
> > > > > At the minimum new Kafka users will pick the Java consumer without
> > any
> > > > > confusion. And existing users will know that Kafka is preparing for
> > the
> > > > > old consumer's retirement.
> > > > >
> > > > > --Vahid
> > > > >
> > > > >
> > > > >
> > > > >
> > > > > From:   Joel Koshy <jjkoshy.w@gmail.com>
> > > > > To:     "dev@kafka.apache.org" <dev@kafka.apache.org>
> > > > > Date:   01/05/2017 06:55 PM
> > > > > Subject:        Re: [DISCUSS] KIP-109: Old Consumer Deprecation
> > > > >
> > > > >
> > > > >
> > > > > While I realize this only marks the old consumer as deprecated and
> > not
> > > a
> > > > > complete removal, I agree that it is somewhat premature to do this
> > > prior
> > > > > to
> > > > > having a migration process implemented. Onur has described this in
> > > detail
> > > > > in the earlier thread: http://markmail.org/message/ek
> v352zy7xttco5s
> > > and
> > > > > I'm
> > > > > surprised that more companies aren't affected by (or aware of?) the
> > > > issue.
> > > > >
> > > > > On Thu, Jan 5, 2017 at 4:40 PM, radai <radai.rosenblatt@gmail.com>
> > > > wrote:
> > > > >
> > > > > > I cant speak for anyone else, but a rolling upgrade is definitely
> > how
> > > > we
> > > > > > (LinkedIn) will do the migration.
> > > > > >
> > > > > > On Thu, Jan 5, 2017 at 4:28 PM, Gwen Shapira <gwen@confluent.io>
> > > > wrote:
> > > > > >
> > > > > > > it sounds good to have
> > > > > > > it, but that's probably not how people will end up migrati
> > > > > > >
> > > > > >
> > > > >
> > > > >
> > > > >
> > > > >
> > > > >
> > > >
> > >
> >
>

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